In recent years, in a semiconductor manufacturing process, further improvement in a fine processing technology using higher integration or higher performance of an element has been required. In the semiconductor manufacturing process, an etching technology is an important one type of fine processing technology types, and in recent years, among etching technologies, a plasma etching technology that forms a fine pattern in a solid material by radicals (free radicals) which are generated from plasma has become mainstream as a technology that is highly efficient and that enables fine processing of a large area.
On the other hand, there is a plasma CVD method, as a type of thin film growth technology in which source gases are combined by the action of plasma and the obtained compound is deposited on a substrate. This method is a film formation method in which plasma discharge is caused by applying a high-frequency electric field to gas including source molecules, then, the source molecules are decomposed by electrons accelerated by the plasma discharge, and the obtained compound is deposited. Even if it is reaction which does not occur just from thermal excitation at low temperature, since gases in a system collide with each other and are activated in plasma, the gases turn into radicals, and thus, reaction can occur.
In a semiconductor manufacturing apparatus using plasma, such as a plasma etching apparatus or a plasma CVD apparatus, in the past, as a device to easily mount and fix a wafer onto a sample stage and also maintain the wafer at a desired temperature, an electrostatic chuck device provided with an electrostatic chuck section that has a placement surface where a wafer is placed, and is made to have an internal electrode for electrostatic adsorption built-in, and a cooling base section that cools the electrostatic chuck section, have been used.
Incidentally, in an existing plasma etching apparatus, it is necessary to raise temperature to a desired temperature by heating a wafer. However, in the temperature rising process, a temperature distribution occurs in the in-plane of the wafer. For example, at a central portion of the wafer, temperature becomes high, and at a marginal portion, temperature becomes low.
Further, a difference occurs in an in-plane temperature distribution of the wafer due to a difference in structure or method of the plasma etching apparatus.
Therefore, in order to reduce the in-plane temperature distribution of the wafer, there is proposed an electrostatic chuck device with a heater function in which a spiral or serpentine heater pattern formed between an electrostatic chuck section and a cooling base section is made to be a two-zone heater pattern which includes an inner heater pattern and an outer heater pattern and the heater patterns of the respective zones are individually controlled (refer to, for example, PTL 1 or the like), a ceramic heater in which an in-plane temperature distribution of an adsorption surface for a wafer is reduced by forming a heater pattern in a plurality of layers in a vertical direction (refer to, for example, PTL 2 or the like), and the like.
The electrostatic chuck device with heater function is obtained by fabricating an electrostatic chuck section with a built-in heater or with a heater mounted therein by a method of having a heater built in an electrostatic chuck section made of ceramic, a method of mounting a heater by coating a heater material on the back side of an adsorption surface of an electrostatic chuck section, that is, the rear surface of a ceramic plate-shaped body in a predetermined pattern by a screen printing method and performing thermal curing, a method of mounting a heater by sticking metal foil or a sheet-like conducting material to the rear surface of a ceramic plate-shaped body, or the like, and bonding and integrating the electrostatic chuck section and a cooling base section that cools the electrostatic chuck section, through an organic adhesive layer.